title: 5-Nitroimidazole-based 1,3,4-thiadiazoles: heterocyclic analogs of metronidazole as anti-Helicobacter pylori agents.
abstract: A series of 5-nitroimidazole-based 1,3,4-thiadiazoles were prepared and tested for antibacterial activity against Helicobacter pylori. The anti-H. pylori activity of target compounds along with the commercially available antimicrobial metronidazole was evaluated by comparing the inhibition-zone diameters determined by the paper disc diffusion bioassay. From our bioassay results against 20 clinical isolates it is evident that piperazinyl, 4-methylpiperazinyl, 3-methylpiperazinyl, and 3,5-dimethylpiperazinyl analogs (6a, 6b, 6e, and 6f, respectively) and pyrrolidine derivative 7 had strong activity at 0.5 µg/disc (average of inhibition zone > 20 mm) while metronidazole had no activity at this dose. Compound 6f containing the 3,5-dimethylpiperazinyl moiety at the 2-position of the 5-(1-methyl-5-nitro-1H-imidazol-2-yl)-1,3,4-thiadiazole skeleton was the most potent compound tested at low concentrations.
authors.affiliation: Department of Microbiology, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Mohammad Hassan
authors.initials: MH
authors.lastname: Moshafi
authors.forename: Maedeh
authors.initials: M
authors.lastname: Sorkhi
authors.forename: Saeed
authors.initials: S
authors.lastname: Emami
authors.forename: Maryam
authors.initials: M
authors.lastname: Nakhjiri
authors.forename: Azadeh
authors.initials: A
authors.lastname: Yahya-Meymandi
authors.forename: Amir Soheil
authors.initials: AS
authors.lastname: Negahbani
authors.forename: Farideh
authors.initials: F
authors.lastname: Siavoshi
authors.forename: Maryam
authors.initials: M
authors.lastname: Omrani
authors.forename: Eskandar
authors.initials: E
authors.lastname: Alipour
authors.forename: Mohsen
authors.initials: M
authors.lastname: Vosooghi
authors.forename: Abbas
authors.initials: A
authors.lastname: Shafiee
authors.forename: Alireza
authors.initials: A
authors.lastname: Foroumadi
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D016480:Helicobacter pylori / Q000187:drug effects*; D008795:Metronidazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009593:Nitroimidazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013830:Thiadiazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D009593:Nitroimidazoles; D013830:Thiadiazoles; D008795:Metronidazole; C052587:4-nitroimidazole